Meiosis Picture Process

This diagram illustrates the complex stages of meiosis, highlighting the key differences from mitosis:

1. Before meiosis begins, chromosomes are copied, with centromeres holding the chromatids together.

2. Meiosis I: Chromosome pairs line up in the middle. Spindle fibers pull the centromeres to opposite sides, separating the pairs.

3. Meiosis II: Chromosomes with two chromatids move to the cell center. Centromeres split and chromatids separate, moving to opposite sides.

4. End of Meiosis: Four sex cells are produced, each with half the number of chromosomes as the parent cell. Each cell has one chromosome from each original pair.

Example: In humans, meiosis produces gametes (sperm or eggs) with 23 chromosomes, half the number in body cells.

Highlight: Meiosis results in genetic diversity through the random assortment of chromosomes and crossing over during prophase I.

Mitosis & Meiosis: How do we make more cells?

This page provides an overview of cell division processes, focusing on the cell cycle and mitosis:

The cell cycle consists of three main stages:

1. Interphase
2. Mitosis
3. Cytokinesis

Interphase is the longest stage where the cell grows, makes a copy of its DNA (DNA replication), and prepares to divide.

Mitosis is the stage where the cell's nucleus divides into two new nuclei, distributing one copy of DNA into each daughter cell. It has four stages: Prophase, Metaphase, Anaphase, and Telophase.

Definition: Homologous chromosomes - Chromosomes that carry the same sets of genes but may have different versions of those genes.

Vocabulary: Chromatin - The loosely structured form of DNA and proteins in the nucleus during interphase.

Highlight: Mitosis is a form of asexual reproduction in unicellular organisms and is used for growth and repair in multicellular organisms.

Example: In humans, mitosis creates body cells with 46 chromosomes, while meiosis produces gametes with 23 chromosomes.

Mitosis Picture Process

The stages of mitosis are clearly illustrated in this diagram, showing the key events in each phase:

Prophase: Chromosomes condense and become visible as the nuclear envelope dissolves. Centriole pairs move to opposite poles and spindle fibers form.

Metaphase: Chromosomes align along the cell's equator, with each attaching to a spindle fiber at its centromere.

Anaphase: Centromeres divide and chromatids (now called chromosomes) move toward opposite poles as the cell elongates.

Telophase: Nuclear envelopes reform around the separated chromosomes at each pole. Chromosomes uncoil and spindle fibers dissolve as cytokinesis begins.

Vocabulary: Centromere - The constricted region of a chromosome that joins the two chromatids.

Highlight: The spindle fibers play a crucial role in aligning and separating chromosomes during mitosis.

Definition: Cytokinesis - The division of the cytoplasm to form two separate daughter cells following nuclear division.